Clinical trials of the world's first anti-smoking vaccine have been launched.

Sixty volunteers will take part in the tests being carried out in Belgium.

If successful, the vaccine, known as TA-NIC, will help smokers to quit by stopping nicotine from reaching the brain, thereby preventing addiction.

A nicotine vaccine would effectively become one of the most important medicines in the response to cancer, lung and heart disease

Clive Bates

At this early stage the tests are simply concerned with establishing what level of dose can be safely tolerated.

According to the World Health Organisation, there are more than a billion smokers worldwide.

It is estimated that about four million die each year because of cancer, heart disease and other smoking related illnesses.

Over the last few years, nicotine chewing gum and patches have become popular as a way of helping people to quit.

However, the new anti-nicotine vaccine works in a completely different way.

Nicotine passes easily into the brain from the blood; and it is then that smokers become addicted to cigarettes.

Immune system

The vaccine is designed to stimulate the body's immune system to produce antibodies which bind to the nicotine molecules.

This makes them too big to get into the brain and so the smoker's addiction subsides.

If the trial succeeds, Xenova, the UK company developing the vaccine, hopes to have it on the market within five years.

David Oxlade, Xenova's Chief Executive, said: "Most people who want to stop smoking find it very hard to do so, even though they may be aware of the risks involved.

"Although at an early stage of development, if TA-NIC can be of assistance it could have an important contribution to make in reducing the burdens that smoking imposes."

Clive Bates, director of Action on Smoking and Health, said: "A nicotine vaccine would be a profound development, which would effectively become one of the most important medicines in the response to cancer, lung and heart disease.

"About a third of smokers, or 4m people, try to quit each year, but the vast majority relapse within days or weeks and start to smoke again.

"If a vaccine helped reduce the relapse rate, then it could change everything.

"If smokers could quit when they wanted to - and most do want to - then the tobacco companies would be dead in the water."

However, Mr Bates warned that the research was at an early stage.

"The trial is about the safety not the effectiveness of
the treatment, and sometimes hype can conceal just how far there is to go.

"No-one should hold back from trying to quit now in the hope there will be a magic potion in a few years."

Xenova is one of several companies researching vaccines against other addictive drugs, including cocaine.